In Situ Generation of Electron Donor to Assist Signal Amplification on Porphyrin-Sensitized Titanium Dioxide Nanostructures for Ultrasensitive Photoelectrochemical Immunoassay.

An ultrasensitive photoelectrochemical (PEC) immunoassay protocol for quantitative detection of low-abundant proteins at a low potential was designed by utilizing porphyrin-sensitized titanium dioxide (TiO2) nanostructures. Experimental results demonstrated that the water-soluble 5,10,15,20-tetra(4-sulfophenyl)-21H,23H-porphyrin (TSPP) could be bound onto titanium dioxide via the sulfonic group. TSPP-sensitized TiO2 nanostructures exhibited better photoelectrochemical responses and stability in comparison with TiO2 nanoparticles alone under continuous illumination. Using carcinoembryonic antigen (CEA) as a model analyte, a typical PEC immunosensor by using TSPP-TiO2 as the affinity support of anti-CEA capture antibody (Ab1) to facilitate the improvement of photocurrent response was developed. Bioconjugates of secondary antibody and glucose oxidase with gold nanoparticles (Ab2/GOx-AuNPs) was introduced by an antigen-antibody immunoreaction. AuNP acted as a powerful scaffold to bind with bioactive molecules, while GOx catalyzed glucose to in situ generate hydrogen peroxide (H2O2). The generated H2O2 as a sacrificial electron donor could be oxidized by the photogenerated holes to assist the signal amplification at a low potential under light excitation, thus eliminating interference from other species coexisting in the samples. Under optimal conditions, the PEC immunosensor showed a good linear relationship ranging from 0.02 to 40 ng mL(-1) with a low detection limit of 6 pg mL(-1) CEA. The precision, reproducibility, and specificity were acceptable. In addition, the method accuracy was also evaluated for quantitatively monitoring human serum samples, giving results matching with the referenced CEA ELISA kit.

[1]  E. Itoh,et al.  Photovoltaic properties of double layer devices consisting of titanium dioxide and porphyrin dispersed hole transporting material layer , 2003 .

[2]  I. Borissevitch,et al.  On the dynamics of the TPPS4 aggregation in aqueous solutions: successive formation of H and J aggregates. , 2006, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[3]  R. Renganathan,et al.  Fluorescence quenching of meso-tetrakis (4-sulfonatophenyl) porphyrin by colloidal TiO(2). , 2008, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[4]  M. T. Martín-Romero,et al.  Soret emission from water-soluble porphyrin thin films: effect on the electroluminescence response , 2009 .

[5]  Bin Liu,et al.  Highly Efficient Nanoporous TiO2‐Polythiophene Hybrid Solar Cells Based on Interfacial Modification Using a Metal‐Free Organic Dye , 2009 .

[6]  Huangxian Ju,et al.  Low-potential photoelectrochemical biosensing using porphyrin-functionalized TiO₂ nanoparticles. , 2010, Analytical chemistry.

[7]  Meicheng Yang,et al.  A photoelectrochemical immunosensor based on Au-doped TiO2 nanotube arrays for the detection of α-synuclein. , 2010, Chemistry.

[8]  Michael Grätzel,et al.  Porphyrin-Sensitized Solar Cells with Cobalt (II/III)–Based Redox Electrolyte Exceed 12 Percent Efficiency , 2011, Science.

[9]  Ravindra K. Pandey,et al.  The Role of Porphyrin Chemistry in Tumor Imaging and Photodynamic Therapy , 2011 .

[10]  T. Bora,et al.  Hematoporphyrin-ZnO nanohybrids: twin applications in efficient visible-light photocatalysis and dye-sensitized solar cells. , 2012, ACS applied materials & interfaces.

[11]  Liyuan Han,et al.  Highly efficient nanoporous graphitic carbon with tunable textural properties for dye-sensitized solar cells , 2012 .

[12]  Jun-Jie Zhu,et al.  Dual-signal amplification strategy for ultrasensitive photoelectrochemical immunosensing of α-fetoprotein. , 2012, Analytical chemistry.

[13]  Reinhard Niessner,et al.  DNA-based hybridization chain reaction for amplified bioelectronic signal and ultrasensitive detection of proteins. , 2012, Analytical chemistry.

[14]  Thomas E Mallouk,et al.  Design and development of photoanodes for water-splitting dye-sensitized photoelectrochemical cells. , 2013, Chemical Society reviews.

[15]  Design and Development of Photoanodes for Water‐Splitting Dye‐Sensitized Photoelectrochemical Cells , 2013 .

[16]  Jinghua Yu,et al.  Chemiluminescence excited paper-based photoelectrochemical competitive immunosensing based on porous ZnO spheres and CdS nanorods. , 2014, Journal of materials chemistry. B.

[17]  Wei-Wei Zhao,et al.  Photoelectrochemical DNA biosensors. , 2014, Chemical reviews.

[18]  C. Freire,et al.  Indigo dye production by enzymatic mimicking based on an iron(III)porphyrin , 2014 .

[19]  Basile F. E. Curchod,et al.  Dye-sensitized solar cells with 13% efficiency achieved through the molecular engineering of porphyrin sensitizers. , 2014, Nature chemistry.

[20]  M. Leung,et al.  In situ deposition of Ag-Ag2S hybrid nanoparticles onto TiO2 nanotube arrays towards fabrication of photoelectrodes with high visible light photoelectrochemical properties. , 2014, Physical chemistry chemical physics : PCCP.

[21]  A. Fujishima,et al.  Photoelectrochemical biosensors: New insights into promising photoelectrodes and signal amplification strategies , 2015 .

[22]  Liguo Wang,et al.  A visible light induced photoelectrochemical aptsensor constructed by aligned ZnO@CdTe core shell nanocable arrays/carboxylated g-C3N4 for the detection of Proprotein convertase subtilisin/kexin type 6 gene. , 2015, Biosensors & bioelectronics.

[23]  J. Nicoud,et al.  Diketopyrrolopyrrole-porphyrin conjugates with high two-photon absorption and singlet oxygen generation for two-photon photodynamic therapy. , 2015, Angewandte Chemie.

[24]  Hongtao Yu,et al.  Fabrication of quantum-sized CdS-coated TiO2 nanotube array with efficient photoelectrochemical performance using modified successive ionic layer absorption and reaction (SILAR) method , 2015 .